Atmega328 MIDI interface for the x0x heart http://www.openmusiclabs.com/projects/x0x-heart/
One-sided for easy home DIY.
The gate pins of the eurorack connector are raised to 5V during the note. The "CV" pins of the eurorack connector are set to 1V/oct pitch control voltage. A pitch scale trimpot can be used to tune the x0x.
| MIDI CC | Function |
|---|---|
| 1 | Envelope |
| 2 | Resonance |
| 11 | Accent |
| 65 | Slide above 64 / No slide below 64 |
| 70 | Saw level |
| 71 | Square level |
| 72 | Decay |
| 74 | VCF Cutoff |
MIDI Sysex messages for this device begin with a four-byte prefix of the Sysex status byte, manufacturer ID, model ID and device ID.
F0 sysex start
77 33 manufacturer ID, model ID
xx device ID as set by trim pot
--
At startup, the MIDI channel of the device is the same as the device ID set with the trim pot.
A seven-byte sysex message can be used to change the channel of the interface.
F0 77 33 xx sysex prefix
00 select MIDI channel parameter
xx new MIDI channel (0 for omni)
F7 end of message
--
A six-byte sysex message can be used to request a dump of the current voice parameters.
F0 77 33 xx sysex prefix
01 patch dump request
F7 end of message
The interface will then send a patch dump sysex message that encodes the current voice parameter values.
F0 77 33 xx sysex prefix
02 patch dump
ee rr aa pp ss qq dd ff
envelope, resonance, accent, slide, saw, square, decay, cutoff (eight bytes)
F7 end of message
This dumped patch data can be used to set all voice parameters by sending it back to the interface.
--
F0 77 33 xx sysex prefix
11 save patch
pp patch number (0-127)
F7 end of message